We developed two distinct forest therapy programs (FTPs) and compared their effects on dementia prevention and related health problems for older adults. One was focused on Qigong practice in the forest (QP) and the other involved active walking in the forest (WP). Both FTPs consisted of twelve 2-h sessions over six weeks and were conducted in an urban forest. We obtained data from 25, 18, and 26 participants aged 65 years or above for the QP, WP, and control groups, respectively. Neuropsychological scores via cognition (MoCA), geriatric depression (GDS) and quality of life (EQ-5D), and electrophysiological variables (electroencephalography, bioimpedance, and heart rate variability) were measured. We analyzed the intervention effects with a generalized linear model. Compared to the control group, the WP group showed benefits in terms of neurocognition (increases in the MoCA score, and alpha and beta band power values in the electroencephalogram), sympathetic nervous activity, and bioimpedance in the lower body. On the other hand, the QP group showed alleviated depression and an increased bioimpedance phase angle in the upper body. In conclusion, both active walking and Qigong in the forest were shown to have distinctive neuropsychological and electrophysiological benefits, and both had beneficial effects in terms of preventing dementia and relieving related health problems for elderly individuals.

The purpose of this study was to examine the effects of exercise intensity and the duration of an exercise-based forest therapy program on physiological changes in older adults. The forest therapy program consisted of 20 sessions over 10 weeks. Forty-one older adults aged 65 years and older were divided into no treatment (daily activity group) and experimental (forest therapy) groups. The experimental group was further divided into the medium-intensity forest exercise group and the high-intensity forest exercise group to analyze physiological changes according to exercise intensity and duration. The physiological changes were analyzed by collecting saliva and measuring changes in the levels of immunoglobulin A and dehydroepiandrosterone, a hormone used to predict aging. Changes within the daily activity group and the forest therapy group after their respective exercises were analyzed using paired t-tests. Saliva testing was performed before and in weeks 5 and 10 of the program and analyzed using a repeated measures analysis of variance to assess the effects of the forest therapy on the medium-intensity forest exercise group and the high-intensity forest exercise group based on the duration of exercise. As a result of the study, a significant increase in immunoglobulin A was observed in the medium-intensity forest exercise group. The daily activity group and the high-intensity forest exercise group showed an increase, but there was very little change and no significance. Changes in dehydroepiandrosterone decreased in the daily activity group and significantly increased in the moderate-intensity forest exercise group at 5 and 10 weeks, showing that regular moderate-intensity forest exercise has an effect on dehydroepiandrosterone. The high-intensity forest exercise group improved over time, but no significant level of change was observed. This study shows that forest exercise has a beneficial effect on immunoglobulin A and dehydroepiandrosterone levels in older adults.